Well, if you're only 200 acres big and you grow by 40 acres, that max pop increase is going to be significant, which means you'll be well under max pop, proportionally at least, meaning your production will drop significantly like I experienced. Maybe this is the only time you'll really see anything meaningful in terms of slowing growth. But if I'm 5k acres and make a big 1k grab, I'll again full pretty far below max pop proportionally (83% in both cases). Only now, instead of 40*12 expanded max population to fill, I'll have 1000*12 to fill, much more.

Now, you may know more than me about population growth formulas. I'm sure you do gain more population per turn if you've got more space below the max population available. So maybe it comes out to roughly the same in terms of how long it takes to reach close to max pop.

It does seem to slow your growth down either way though. It seems that making 5 grabs of 200 acres, in any case, is somewhat closer to making 1 grab of 1000 acres than it used to be. Maybe not to a significant degree... not sure...